To find that you have no hot water is more than a nuisance!
No water at all?
Firstly, is the water running cold, or is there no water coming out of the tap. If there is no water coming out of the tap there is usually a blockage or an airlock, both of which may need professional help to find. But, check all the taps, both cold and hot. If no water is coming out of any of them, it’s usually a problem outside your house. Go and see whether your neighbours have any water. A call to the water supplier will normally get some help and the water supply reinstated.
Do you have a hot water cylinder and a separate boiler?
If so, the first thing to check is whether the timer is on (usually indicated by a light showing on water). Then go to the boiler and see whether this is working.
If the programmer is on and switched to the water position, but the boiler is not working then it is likely that you have a boiler fault and will need an engineer to have a look. Try running the heating. If the heating works, but not the hot water, the fault could be with the valve that switches between heating and hot water (this also switches the boiler on and off), but this will also require and engineer to visit to solve the problem.
Do you have a combination boiler?
This is the type of boiler that heats the water only when a tap or shower is turned on – no separate hot water cylinder is fitted.
Most faults on a combi boiler need an engineer to visit. But firstly, check the water pressure guage. If the pressure in the system falls low (usually below about .5 bar) the boiler will stop working to protect itself. In some cases there will be a fault code displayed which you can look up online or in the boiler’s manual. You can top up the pressure yourself, and there are many helpful videos on YouTube showing how. Don’t attempt it unless you are sure you know how as too much pressure can cause damage to the boiler.
With both systems, we occasionally come across faults that are caused by the gas being accidentally turned off at the gas meter, usually when something falls onto the isolation valve! The isolation valve near the meter should be in the position with the handle in line with the pipe. But call us or your gas supplier before altering it. Safety first!